From KU Leuven and the “department of annoying back-radiation” comes this claim that flies in the face of the “big melt” under “thin clouds” aka nearly clear skies back in July 2012
Clouds play a bigger role in the melting of the Greenland ice sheet than was previously assumed. Compared to clear skies, clouds enhance the meltwater runoff by a third. Those are the findings of an international study that was coordinated by KU Leuven and published inNature Communications.
Greenland’s ice sheet is the second largest ice mass in the world – the largest is Antarctica. The ice sheet is losing mass at a high speed and increasingly contributes to the sea level rise on our planet. The role of clouds in this loss of snow and ice has never been calculated before, nor can it be deduced from theoretical climate models. For lack of observations, the different models do not agree on the importance of clouds over the ice sheet.
“Clouds always have several effects”, lead author Kristof Van Tricht explains. “On the one hand, they help add mass to the ice sheet when it snows. On the other, they have an indirect effect on the ice sheet as well: they have an impact on the temperature, and snow and ice react to these changes by melting and refreezing. That works both ways. Clouds block the sunlight, which lowers the temperature. At the same time, they form a blanket that keeps the surface warm, especially at night. In this study, we examine the net result of these two indirect effects on the entire Greenland ice sheet.”
The researchers used specific satellite observations to detect clouds over the Greenland ice sheet from 2007 to 2010. They compared the results with ground-based observations. The researchers combined these observations with snow model simulations and climate model data to map the net effect of clouds.
“Over the entire Greenland ice sheet, clouds raise the temperature, which triggers additional meltwater runoff: 56 billion tons per year – a third more than clear skies. Contrary to what you would expect, this effect is not so much visible during the daytime melting process, but rather during the following night. A snowpack is like a frozen sponge that melts during the day. At night, clear skies make a large amount of meltwater in the sponge refreeze. When the sky is overcast, by contrast, the temperature remains too high and only some of the water refreezes. As a result, the sponge is saturated more quickly and excess meltwater drains away.”
The study highlights the need for accurate cloud representations in climate models that aim to estimate the amount of meltwater. “With climate change at the back of our minds, and the disastrous consequences of a global sea level rise, we need to understand these processes to make more reliable projections for the future. Clouds are more important for that purpose than we used to think.”
###
Who would have guessed that clouds would have affected temperature! /s
No one who worked on the IPCC report.
MarkW,
Why would you write such a ridiculously easy to falsify statement?
TAR: https://www.ipcc.ch/ipccreports/tar/wg1/507.htm
14.2.3.1 Clouds
The role of clouds in the climate system continues to challenge the modelling of climate (e.g., Chapter 7, Section 7.2.2). It is generally accepted that the net effect of clouds on the radiative balance of the planet is negative and has an average magnitude of about 10 to 20 Wm-2. This balance consists of a short-wave cooling (the albedo effect) of about 40 to 50 Wm-2 and a long-wave warming of about 30 Wm-2. Unfortunately, the size of the uncertainties in this budget is large when compared to the expected anthropogenic greenhouse forcing. Although we know that the overall net effect of clouds on the radiative balance is slightly negative, we do not know the sign of cloud feedback with respect to the increase of greenhouse gases, and it may vary with the region. In fact, the basic issue of the nature of the future cloud feedback is not clear. Will it remain negative? If the planet warms, then it is plausible that evaporation will increase, which probably implies that liquid water content will increase but the volume of clouds may not. What will be the effect and how will the effects be distributed in time and space? Finally, the issue of cloud feedbacks is also coupled to the very difficult issue of indirect aerosol forcing (see Chapter 5, Section 5.3).
The importance of clouds was summarised in the SAR: “The single largest uncertainty in determining the climate sensitivity to either natural or anthropogenic changes are clouds and their effects on radiation and their role in the hydrological cycle” (Kattenberg et al., 1996, p.345). And yet, the single greatest source of uncertainty in the estimates of the climate sensitivity continues to be clouds (see also Chapter 7, Section 7.2).
AR4: https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-6-3-2.html
8.6.3.2 Clouds
By reflecting solar radiation back to space (the albedo effect of clouds) and by trapping infrared radiation emitted by the surface and the lower troposphere (the greenhouse effect of clouds), clouds exert two competing effects on the Earth’s radiation budget. These two effects are usually referred to as the SW and LW components of the cloud radiative forcing (CRF). The balance between these two components depends on many factors, including macrophysical and microphysical cloud properties. In the current climate, clouds exert a cooling effect on climate (the global mean CRF is negative). In response to global warming, the cooling effect of clouds on climate might be enhanced or weakened, thereby producing a radiative feedback to climate warming (Randall et al., 2006; NRC, 2003; Zhang, 2004; Stephens, 2005; Bony et al., 2006).
In many climate models, details in the representation of clouds can substantially affect the model estimates of cloud feedback and climate sensitivity (e.g., Senior and Mitchell, 1993; Le Treut et al., 1994; Yao and Del Genio, 2002; Zhang, 2004; Stainforth et al., 2005; Yokohata et al., 2005). Moreover, the spread of climate sensitivity estimates among current models arises primarily from inter-model differences in cloud feedbacks (Colman, 2003a; Soden and Held, 2006; Webb et al., 2006; Section 8.6.2, Figure 8.14). Therefore, cloud feedbacks remain the largest source of uncertainty in climate sensitivity estimates.
This section assesses the evolution since the TAR in the understanding of the physical processes involved in cloud feedbacks (see Section 8.6.3.2.1), in the interpretation of the range of cloud feedback estimates among current climate models (see Section 8.6.3.2.2) and in the evaluation of model cloud feedbacks using observations (see Section 8.6.3.2.3).
AR5: https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter07_FINAL.pdf
7.1.2
Rationale for Assessing Clouds, Aerosols and Their Interactions
The representation of cloud processes in climate models has been recognized for decades as a dominant source of uncertainty in our understanding of changes in the climate system (e.g., Arakawa, 1975, 2004; Charney et al., 1979; Cess et al., 1989; Randall et al., 2003; Bony et al., 2006), but has never been systematically assessed by the IPCC before. Clouds respond to climate forcing mechanisms in multiple ways, and inter-model differences in cloud feedbacks constitute by far the primary source of spread of both equilibrium and transient climate responses simulated by climate models (Dufresne and Bony, 2008) despite the fact that most models agree that the feedback is positive (Randall et al., 2007; Section 7.2). Thus confidence in climate projections requires a thorough assessment of how cloud processes have been accounted for.
You must have been dying to throw that back at a denier for quote a while.
I guess Brandon Gates doesn’t enjoy playful, toss-away or tongue-in-cheek comments.
Not really, I see such low-hanging fruit almost daily.
A.D. Everard,
I enjoy them just fine when it’s perfectly clear to me that the other guy really is kidding. I’ve read, “climatologists ignore X” so often as part of an earnest argument, and so often pointed out how wrong that is with no apparent effect that, unfortunately, my default assumption is that people aren’t goofing when they say things like that here.
So why would it be helpful to the cause to point out that climate models are fraught with uncertainty and large error bars because they fail to adequately account for the role of clouds in forecasts of warming and climate sensitivity?
Because some people when confronted with the statement, “We don’t have the foggiest idea what will happen if we do X” might conclude that we shouldn’t do X until we better understand the consequences of doing it.
The comment was silly but so is this one —
““We don’t have the foggiest idea what will happen if we do X” might conclude that we shouldn’t do X until we better understand the consequences of doing it.”
So we shouldn’t slash our energy production until we understand what it will do to us economically and whether it will have any beneficial impact to the environment right?
“Unfortunately, the size of the uncertainties in this budget is large when compared to the expected anthropogenic greenhouse forcing.”
Talk about a smoking gun. It basically says that the GCM’s are large piles of male bovine excrement unless clouds can be modeled correctly.
Jeff Id,
No matter how bad either of us think climate models are, I would argue that macroeconomic models (and they come in many, often contradictory, flavors) are worse. But, as bad as I think the sum total of economic models are, I will say with a fair amount of confidence that slashing energy production would end badly for a lot of people.
Mr. 1984,
read the caption on the picture:(Clouds over Greenland raise the temperature of the ice). I guess the author would have you believe that clouds over Greenland effect the temperature. Who needs the sun
I really don’t know clouds at all:
Duh. I guess they never spent time in a cold climate where radiation cooling on a clear night can dramatically drop temperatures, while cloud cover keeps the nights warmer. The reason is that GHG’s are narrow band absorbers and emitters, while clouds are broad band absorbers and emitters. On a clear night, about half of the spectrum is available to transmit power from the surface into space. Think of the clear sky as a greenhouse with half of the roof panels removed.
Does anyone know how much of the cloud ‘warming effect’ is due to downwards IR versus the simple release of latent heat that happens as the water vapor in the cooling cloud condenses into water droplets?
Bernard,
It’s counterproductive and misleading to isolate one effect of water from the others. Evaporation. latent heat, clouds and weather are all intimately tied together in a global sense. Locally, clouds keep the surface warmer by reducing the heat that escapes into space. Globally, the net effect of evaporation and weather is cooling consequential to a negative feedback like effect from the heat engine driving weather and that uses water as its refrigerant. Hurricanes are the existence proof of this which would otherwise, leave a trail of warm water in their wake. And of course, the second law tells us that a heat engine can not warm its source of heat, which in the case of the weather is the surface. The heat released as water condenses in the atmosphere warms the water being condensed and is the primary source of the energy that drives weather. This warmed water ultimately falls to the surface as rain that is warmer than the lapse rate would suggest it should be based on the altitude where it condensed.
but, but, but… the science was settled.
Yes, but their version is that it’s settled AND changing. You know, just like their global warming causes hot and cold and droughts and floods and snow and everything in between. They just grab everything and throw it in and soon they’ll have it all, then no one can say it isn’t settled because everything will be included. So it must be.
Does that sound like a valid theory?
in a word : no
Dang. Back to the drawing board.
It’s a typo. The science is saddled.
Prove it.
{All the data says otherwise.}
… create a mess proving exactly: nothing.
Oh. Brother. More JUNK science about the “sponge” effect and describing Greenland as if it is a drain on a city street, plugged by ice, so when it rains, the street will FLOOD. (Cf. Brother Colgan’s junk science, here:
)
(Source: http://wattsupwiththat.com/2016/01/04/failed-claim-right-out-of-the-gate-climate-change-altering-greenland-ice-sheet-accelerating-sea-level-rise/ )
Pretty ironic, public tax money “sponge”{ers}.
Yo, researcher dude. How about SUPPORTING this wild generalization with some evidence. No, model simulations are not “evidence.”
Congratulations, Tricky. Another make-work for money pile of junk. Pretty nice way to make a living, hm?
Heh. They need a SPONGE to wipe up their AGW-driven mess. Pathetic.
It’s truly amazing the number of researchers that apparently never walked around outside at various times of the day during winter and “noticed” stuff. Its sort like the TV weather forecasters that neglect to walk outside before pronouncing on the chance of rain.
My observation is the air T can be well below freezing with zip melting, out comes the sun, and, despite below freezing air, the snow begins to melt rapidly as the short wave energy thermalizes it’s energy against the surface.
Often in the evening, even if warmer then it would otherwise be due to cloud coverage, there is zero melting as the air T is still below freezing. I live in Northern California at 5700′ elevation, and observe this often.
A great time to make snowballs, as I recall, esp from the plowed snow on streetside piles…
I keep saying, water is becoming the next demon of climate change now that Paris has settled the CO2 problem.
Anybody who has ever ventured outdoors in the winter when the ground is covered with snow should know that an overcast sky is like a blanket – it keeps you warm at night by blocking outgoing radiation, but keeps you cool during the day by blocking incoming radiation.
Yeah. Like, “So. You spent HOW much money on this?? To tell us…. what any observant 6-year-old could tell you.” Great.
you left off the sarc tag.
But if you were actually serious, I don’t know what planet you live on. I have lived in NE china for 11 years and believe me, it is not warmer under clouds when the airtemp is -14 deg.
When it’s minus 14 under clouds, it’s exactly the same temperature as when it’s minus 14 degrees in the sunshine
Ice melts and flows from Greenland there
like ice cream castles in the air
and Moulin Canyons everywhere
we’ve looked at clouds that way.
But now they only block the sun
They rain and snow on everyone
So many things models haven’t done
’cause clouds got in their way
We’ve looked at clouds from both sides now
From up and down, and still somehow
It’s climate illusions We recall
We really don’t know clouds at all
(apologies to Joni)
((APPLAUSE!)) Thanks for the little fun time I had singing it , too. 🙂
Me too. I sang along with it.
Well done! +10 for this parody.
Yes, if by “high speed” they mean, if it were to continue melting at the current rate for 800 years about 1% of it would be gone. Horrors. This is all just a ploy for more Alarmist climate funding.
https://rclutz.wordpress.com/2015/10/29/greenland-is-melting-really/
No, not only high speed but accelerating speed, look at this exponential fit on satellite measured mass loss during the last x years.
Don’t look behind the curtain where the GIA stands.
After the Zwally paper I have difficulties with believing in correct calibration when incorrect calibration has so electrifying effects on activists.
Losing mass at a high speed. Well, the net loss was essentially zero in 2014, and will in all likelihood have gained about 200GT in 2015 based on DMI surface mass axcumulation when NASA’s Greenland report card comes out later this week (usually around Jan 15). Don’t have access to Greenland cloudiness for those years compared to 2007-2010. But bet not a lot different. Which would say stuff other than night time summer clouds is more important to Greenland’s ice sheet and its net mass balance.
The researchers used specific satellite observations to detect clouds over the Greenland ice sheet from 2007 to 2010. They compared the results with ground-based observations. The researchers combined these observations with snow model simulations and climate model data to map the net effect of clouds.
Where did all the ground-based observations come from????
As far as I know, Summit Camp is the only place on the Greenland icecap that can do year-round observations. Everyone else (all 56,000) lives away from the icecap.
Net result: model based on fantasy.
this effect is not so much visible during the daytime melting process, but rather during the following night
************************
as anyone who lives in a cold icy place can tell you.
direct sunlight a few hours a day helps, clouds quickly following and covering area for many hours then does most of the work.
Here is the thing, the average annual temperature of Greenland is approximately -17 degrees C, and even the warmest month is well below freezing; as well, the average surface height of the ice cap is 1.3 miles high. How in the world is that ice cap even melting whether it is under clouds or under a clear blue sky?
according to climate science, if you warm ice from -17C to -16C, you get: “the disastrous consequences of a global sea level rise”
lol +1
Sublimation.
Yes, of course, sublimation. But that isn’t melting is it, as was claimed in the paper: “Over the entire Greenland ice sheet, clouds raise the temperature, which triggers additional meltwater runoff: 56 billion tons per year – a third more than clear skies. …”
Sublimation isn’t melting, is it? In England in the winter I would hang out the washing on the line. It would freeze as stiff as a board but end up dry and sweet smelling thanks to sublimation.
Brandon Gates -“I’m going to say this again: a mean tells us nothing about the range. Jesus, Mary and Joseph, this is Remedial Statistics for Absolute Idiots material I’m talking about here.”
Stop your crap. You rebutted the claim of -17C with a choice selection of temperatures at coastal communities. Nobody is trying to tell you that ice doesn’t melt in Greenland. You can’t extrapolate coastal melting to the whole continent. Do you even know what is being claimed about the ice in Greenland?
BTW, your pictures are from the coastal areas, near the Petermann Glacier. The average high and low in Thule nearby in August is 6.2 and 3.8°C respectively. Just to point out to idiots like yourself, global warming of 1°C since the beginning of the IR means that August averages were above 0 even at preferred CO2 levels.
FJ Shepherd,
http://www.greenland.com/media/3893/middeltemperaturer-greenland-dot-com.jpg
Whenever discussing the mean, don’t forget to think about the RANGE. So not only is not all of the Greenland icecap 1.3 miles high (it extends almost all the way to the coast) neither are diurnal temps fixed at below freezing temperatures in all areas every day of the year:
http://www.greenland.com/en/about-greenland/nature-climate/the-weather-in-greenland/mean-temperatures/
Greenlandic mean temperatures
The table shows mean temperatures in most of the towns in Greenland measured in degrees Celsius. As these are 24-hour mean temperatures, the average daytime temperature will be a little higher, whilst the average nighttime temperatures will be a little lower.
At the same time, there can be large fluctuations from day to day; for example in the summer months there are several places in Greenland where day temperatures can exceed 20° C (68° F).
I’ve seen too many of these sorts of photos …
http://www.messagetoeagle.com/images/hiddenriversgreenland02.jpg
… to seriously believe that they’ve all been photoshopped. For Pete’s sake, I don’t need the above temperature data for it to occur to me that some parts of the Greenland ice sheet must experience above freezing weather during some months of the year. The photographic evidence alone really should tell you that much.
Brandon, mate, you can not use a few coastal towns to debunk that most of the ice surface is -17°C. You can’t use a picture of a river on ice to prove that AGW is real. We probably don’t have such photos from the time of the Vikings because the camera was not invented..
My dear Brandon Gates, you can not use coastal communities to prove a warmer temperature range for that is not where the ice cap resides. The coastal areas of Greenland are classified as having a polar tundra climate. The majority of Greenland where the permanent ice sheet resides, 80% of the island, is classified as a polar ice cap climate. In a polar cap classification, the average temperature of EVERY MONTH of the year does not rise above freezing.
As for the coastal area, the polar tundra area, no month in the year averages a temperature above 10 degrees C. The warmest spot in Greenland, with the warmest annual mean temperature is Nanortalik at 1.1 degrees C, way in the warmer south. And sure, at Nanortalik, the August mean temperature is 6.5 degrees C, and sure, the snow disappears for a few months of the year. Big deal. As for that picture of a river flowing through ice, I hope that is not how you determine the “truth” of AGW. You might as well listen to Bill McKibben who has claimed for the last two years that “we have already melted the Arctic.” From Bill, we can learn when exaggeration turns into a lie.
Btw Brandon Gates, considering the source of that photo with a river flowing through a canyon of ice, I suppose you also believe in this sort of nonsense coming from the exact same website:
http://www.messagetoeagle.com/can-dramatic-climate-changes-throughout-our-solar-system-trigger-spontaneous-evolution/
Please consider your sources before posting them. This could prove to be rather embarrassing to you.
Robert B,
Of course not, but I can use it to point out that:
1) a mean says nothing about the range
2) not all of Greenland is is a one-mile high ice cap.
Again, of course not, but I can use a picture of a river on ice to demonstrate that Greenland ice is indeed melting from the surface down in some places.
Um, true, but what in the heck does that have anything to do with what is going on today? I’ve got photographic evidence of the NOW, seems I should be able to use it to demonstrate what is happening NOW.
FJ Shepherd,
Of course not, but from that data, combined with photographic evidence that portions of the Greenland icecap are presently melting during summer months, I believe I can reasonably infer that some portions of the ice cap do indeed exceed the freezing point of water at some point during the year.
Those classifications are generated using observational data, correct? It should be a simple matter for you to provide a citation to the obsevational data used to derive those classifications, then everyone reading can go look at the data and decide for themselves.
Perhaps these climate changes are related to Nibiru, Wave X, or any given cosmic wildcard, but when events like these occur, it’s important to take notice.
I really should have stopped reading right there, but curiosity got the better of me and I read the whole article. No, I don’t believe it.
I chose that photo because I thought it was especially pretty. But there are other ones:
Source: wattsupwiththat.com
Should I be embarrassed?
http://cpo.noaa.gov/sites/cpo//EasyDNNNews/thumbs/48/89meltwater_NWgreenland_SWIPA_HR.jpg
Source: cpo.noaa.gov
Should I be embarrassed?
http://a57.foxnews.com/images.foxnews.com/content/fox-news/science/2012/11/30/icy-greenland-melting-at-accelerating-rate-study-finds/_jcr_content/par/featured-media/media-2.img.jpg/876/493/1422479115251.jpg
Source: foxnews.com
Should I be embarrassed?
Source: nasa.gov
Should I be embarrassed?
Do I need to do more of this this before you literally get the picture and we can dispense with this silliness that Greenland ice cannot possibly melt because it’s always below freezing there, and you further embarrass yourself by digging in your heels on it?
Cool pics Brandon,
Do you think they are something unusual ?
Or have we just ventured out there with some good cameras ?
Well Brandon Gates, if you want to do a little work on a spreadsheet, you can find out the average temperatures of Greenland by going here:
http://sdwebx.worldbank.org/climateportal/index.cfm?page=global_map
Since even the warmest month, July, has an average temperature of -2.1 degrees C, and since the coastal area (20% of the surface area of Greenland) would have an average temperature in July of over 0 degrees C, at least in the south, you can imagine that the average temperature of the ice cap is lower than -2.1 degrees C.
Perhaps the dataset from Climatic Research Unit (CRU) of University of East Anglia is corrupt and shows too much cooling? LOL! That is a possibility, as is the possibility that those photos are fake. As for photos shown by NASA and NOAA, I would question their validity, in just the same way that I would question anything people like Bill McKibben continue to repeat: “We have already melted the Arctic.”
u.k(us),
Yup, lots of ice and ice cold water. Brrrrrrr.
I don’t have any ready way of knowing that. But I can guess that if we had ventured out there with cameras 10,000 years ago, we’d have gotten some very similar shots since temps during the Holocene optimum were rather close to what they are today … that is, if we are to believe, oh, Marcott et al. (2013) and HADCRUT4:
http://skepticalscience.com//pics/regemcrufull.jpg
A side note, I’ve always found it odd that folks in this forum are generally down on that paper because it shows a rather robust MWP and LIA in addition to a Holocene maximum which the authors say is not statistically different enough from today to call lower or higher with any certainty.
Obviously they’re pretty good cameras, I mean some of those shots are gorgeous. And that evidence really ought to be enough for the likes of FJ Shepherd here who keeps insisting that it’s impossible for there to be any meltwater on Greenland’s ice sheet bbbbbecause according to him, average temps everywhere in Greenland are below freezing year-round — which is the ONLY reason I posted them to begin with.
FJ Shepherd,
I’m going to say this again: a mean tells us nothing about the range. Jesus, Mary and Joseph, this is Remedial Statistics for Absolute Idiots material I’m talking about here.
Gee, I didn’t see that coming. It is interesting that you trust all that “corrupt” data when it allows you to “prove” things are cold though, innit.
The ones from Fox News, or this very website weren’t enough for you? Do I need to find ones posted by Brietbart or Drudge?
Well, you’re in luck, I can’t find any. That tears it, Fox News was snookered and posted a doctored photo. I suggest you pen a very angry letter to Mr. Murdock.
On that note, if you’ve got a problem with something Bill McKibben has to say, complain to him about it, not me. I’m not his personal apologist, and I reserve the right to hold my own opinions and make my own arguments. Thanks.
Ooops. Posted reply in the wrong spot.
Brandon Gates -“I’m going to say this again: a mean tells us nothing about the range. Jesus, Mary and Joseph, this is Remedial Statistics for Absolute Idiots material I’m talking about here.”
Stop your crap. You rebutted the claim of -17C with a choice selection of temperatures at coastal communities. Nobody is trying to tell you that ice doesn’t melt in Greenland. You can’t extrapolate coastal melting to the whole continent. Do you even know what is being claimed about the ice in Greenland?
BTW, your pictures are from the coastal areas, near the Petermann Glacier. The average high and low in Thule nearby in August is 6.2 and 3.8°C respectively. Just to point out to idiots like yourself, global warming of 1°C since the beginning of the IR means that August averages were above 0 even at preferred CO2 level
LOL! Dear Brandon Gates, I was wondering when the nastiness was going to come out. It usually does from you climate alarmists, eventually.
As for mean monthly temperatures, they do give a pretty good guide as to what kind of melting can be done in a region. For instance, I live in a continental climate wherein the monthly mean temperature for January is about the same as for the July monthly mean temperature for Greenland. I can assure you that when snow falls here in January, it stays. Sure, we might receive a thaw for a few days, but that is never enough to remove the white from the ground or cause any kind of major melting. Those pictures show major, major long term warming for the Greenland ice cap to produce what they show. You can believe them if you want. I choose to say such is not possible given the temperature data.
Robert B,
Stop your crap. I rebutted the notion that a mean value says anything about the range of values.
Go back to the first post of this subthread and read more carefully this time:
FJ Shepherd
January 12, 2016 at 1:28 pm
Here is the thing, the average annual temperature of Greenland is approximately -17 degrees C, and even the warmest month is well below freezing; as well, the average surface height of the ice cap is 1.3 miles high. How in the world is that ice cap even melting whether it is under clouds or under a clear blue sky?
lol, I wasn’t trying to. Geez, you are the master of stuffing words I didn’t say into my mouth, aren’t you.
This paper makes the claim that, on average, Greenland lost 33% more ice when it was cloudy than it did under clear skies from 2007 to 2010. Other research indicates that between 2003 and 2013, Greenland has been losing ice mass at an accelerating rate:
http://climexp.knmi.nl/data/idata_grs.png
Oh, and there’s this:
http://onlinelibrary.wiley.com/doi/10.1002/2015GL065912/abstract
Neither dust nor black carbon causing apparent albedo decline in Greenland’s dry snow zone: Implications for MODIS C5 surface reflectance
Abstract
Remote sensing observations suggest Greenland ice sheet (GrIS) albedo has declined since 2001, even in the dry snow zone. We seek to explain the apparent dry snow albedo decline. We analyze samples representing 2012–2014 snowfall across NW Greenland for black carbon and dust light-absorbing impurities (LAI) and model their impacts on snow albedo. Albedo reductions due to LAI are small, averaging 0.003, with episodic enhancements resulting in reductions of 0.01–0.02. No significant increase in black carbon or dust concentrations relative to recent decades is found. Enhanced deposition of LAI is not, therefore, causing significant dry snow albedo reduction or driving melt events. Analysis of Collection 5 Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data indicates that the decline and spectral shift in dry snow albedo contains important contributions from uncorrected Terra sensor degradation. Though discrepancies are mostly below the stated accuracy of MODIS products, they will require revisiting some prior conclusions with C6 data.
Translation: it’s not as bad as we thought.
There are a lot of claims about what’s going on in Greenland because it is being extensively studied, and I could go on like this for quite some time. Perhaps you should tell me which one you are specifically thinking of instead of asking an extremely open-ended question with very little specific context.
Thank you for making my point for me. Now tell it to our dear FJ Shepherd here, because he obviously isn’t getting it.
Just to point out to innumerates like yourself, I repeat something I wrote elsewhere to David A.:
It’s not time above or below a certain fixed threshold, but the frequency distribution of all experienced temperatures. By way of illustration: all else being equal, a liter of liquid water will freeze solid faster when ambient temperature is -40 C than it would in -5 C ambient temperature. The converse is true for the melting process, higher ambient temps will melt the same block of ice faster than temps only slightly above freezing.
Extremes matter. Time spent at particular absolute values matter. Appealing to a mean value here only maybe gives us a very crude yardstick to measure overall change, it does not necessarily tell us about the rate of localized temperature-dependent physical processes because there are all kinds of non-linearities involved when talking about atmospheric and oceanic interactions with ice sheets.
FJ Shepherd,
I’m not entirely sure that we “climate alarmists” have a monopoly on that:
Bruce Cobb
January 12, 2016 at 4:14 pm
You are being disingenuous. The models are pure, unadulterated crap. Trying to “improve” them by putting lipstick on them doesn’t change the fact that they are crap. What they are doing isn’t science at all. The agenda is simply keeping the CAGW gravy train rolling along for at least a bit longer.
Brandon Gates
January 12, 2016 at 5:02 pm
Yeah, those high-falutin libruhl warmunists must be pretty stoopid to have not been able to have come up with a better scam. I mean, 1988 was how long ago and there’s still no worldwide carbon tax? Dang man, they’re fat rolling in your money. And they must be egregiously incompetent to have not thought about tweaking the already falsified surface temperature records so as to better match the output of the imaginary “physics” coded into those models, eh?
Bruce Cobb
January 13, 2016 at 4:30 am
Poor, delusional Brandon, heroically defending his “models”, not realizing that they aren’t reality- based, but rather that a large component of the climate “forcing”, via man’s CO2 is simply assumed.
I dunno, what’s more “nasty”: imputing motive with unsupported accusations of malfeasance or a satirical response to same? Subjective judgement call, I’d warrant. But hey, if tone trolling me makes you feel better about your previously apparently abhorrent grasp of basic statistics, knock yourself out.
Sure, but if and ONLY IF at some point in time local temperatures rise above the melting point. That’s YOUR argument, right? So for that kind of analysis, you must know something about the distribution of all temps at that location. Then you have to make the assumption that changing the mean doesn’t change the distribution of those values relative to the mean. It’s not a terrible way to do it, and in many cases might give a useful answer.
Now you’ve just added another assumption: that your continental climate in winter contains a similar distribution of temperature values as Greenland in July, something which does not necessarily follow. From that leap of logic you imply a conspiracy exists to falsify photographic evidence showing that Greenland ice does indeed melt during the summer.
Sorry for being nasty, but I think that argument is borderline bonkers.
You created a strawman argument that the temperature never gets over 0°C in Greenland because you had nothing else. Only 81% of Greenland is the ice sheet. The rest gets covered in snow in Winter that melts in Summer.
Innumerate? Would you like to show us the calculations for how long it would take a pond to freeze with 1 day at -40 then one day at -10, and days a constant -20? Remember that the surface will freeze over first and then loss of heat to the atmosphere is reduced. Make sure that you don’t forget humidity, wind and the initial temperature of the ice its on.
Robert B,
Um, no. Again here is the comment which started this subthread:
FJ Shepherd
January 12, 2016 at 1:28 pm
Here is the thing, the average annual temperature of Greenland is approximately -17 degrees C, and even the warmest month is well below freezing; as well, the average surface height of the ice cap is 1.3 miles high. How in the world is that ice cap even melting whether it is under clouds or under a clear blue sky?
FJ Shepherd authored that post, not me.
What’s that got to do with the price of tea in China?
This is snow in Greenland …
http://www.iceagenow.com/Kuummiut,%20Greenland.jpg
This is Petermann Glacier in Greenland …
http://binscorner.com/mails/b/blue-river-petermann-glacier/part-020.jpeg
Last I checked, glaciers are made of ice. A river runs through this one in summer. I would not be surprised to learn that particular ice river has formed every summer since the beginning of the Holocene, but whether or not that is the case, that is not the argument I am responding to on this subthread.
Yeesh.
Borderline illiterate is another possibility as well.
I can’t do calculations when not all the input parameters are specified. How deep is the pond? What is its area? Total volume? Is it a stagnant pond, or is there an inlet and outlet? If yes, what’s the flow rate of the water in and out? Temperature of the inlet stream? What latitude is it at? Apropos the OP, how much cloud cover can we expect?
Is this a quiz about whether I’m numerate, or about whether or not I’m a decent environmental engineer?
And yes, Robert B, I know that doing physical models is hard. Thank you for once again changing my argument to suit your own purposes, whatever they may be.
You are calling me illiterate for using the word “innumerate” in a reply to your use of the word “innumerates” for people who (supposedly) didn’t understand the physics rather than mathematical misunderstanding?
Go on. Pretend that it was obvious that you wrote something else.
Anthony,
This study:
“Clouds always have several effects”, lead author Kristof Van Tricht explains. “On the one hand, they help add mass to the ice sheet when it snows. On the other, they have an indirect effect on the ice sheet as well: they have an impact on the temperature, and snow and ice react to these changes by melting and refreezing. That works both ways. Clouds block the sunlight, which lowers the temperature. At the same time, they form a blanket that keeps the surface warm, especially at night. In this study, we examine the net result of these two indirect effects on the entire Greenland ice sheet.”
2013 study:
Low-level clouds typically reflect solar energy back into space, and snow cover also tends to bounce energy from the sun back from the Earth’s surface.
Under particular temperature conditions, however, clouds can be both thin enough to allow solar energy to pass through to the surface and thick enough to “trap” some of that heat even if it is turned back by snow and ice on the ground.
Hmm, I’m not seeing the glaring contradiction.
This study:
The researchers used specific satellite observations to detect clouds over the Greenland ice sheet from 2007 to 2010. They compared the results with ground-based observations. The researchers combined these observations with snow model simulations and climate model data to map the net effect of clouds.
“Over the entire Greenland ice sheet, clouds raise the temperature, which triggers additional meltwater runoff: 56 billion tons per year – a third more than clear skies.
Nope, still not seeing the glaring contradiction. Way I’m reading this, all they are saying is that over the period of time considered, the NET effect of the types of clouds which formed over Greenland caused a 33% increase in melt rate over clear sky conditions during the same interval.
The main difference between these two studies as far as I can tell is that the 2013 study focused on a particular type of low thin cloud layer during a year (2012) when the presence of that particular type was anomalously high whereas the present study apparently considered more “normal” conditions over a period of four years and was concerned with the net effect of all cloud types typically seen over Greenland.
Looks like perfectly good, iterative science to me, particularly since the authors of both papers say that their research is largely aimed at improving especially poor climate model performance in the Arctic. It’s very unclear to me what the fuss is all about here — isn’t this exactly the sort of non-GHG, non-anthropogenic physical mechanism you and your stable of guest posters are frequently complaining that “teh muddulz” are NOT properly accounting for?
…33% of nothing is still nothing !
Your idea of what constitutes properly conducted experiments and observations is not that of bona fide scientists. Or did you overlook Tricky’s shoddy methods?
Further, to add another layer of junk to the junk pile, as Billy Liar points out above, those ground observations are not likely representative.
Sorry. If the defense expert witness on the stand says: stomach ulcers are caused by bacteria and oxygen is 21% of the atmosphere AND LEPRECHAUNS CAN MAKE CLIMATE CHANGE HAPPEN and ice starts to melt around 33 F and at the speed of light, we would reach the moon in about 1.3 sec AND GREENLAND IS MELTING RAPIDLY… DISASTROUS TO HUMANITY IF SEA LEVELS RISE… and in my expert opinion, Acme Pharmaceutical Corp. did not copy its formula from Bigtime Pharmaceutical.
Not convincing.
Except to you, of course, Mr. Gates.
Send him some Snuggies Janice, he’ll probably like them !!!
I would not do that even to Mr. Gates, lol. For one thing…. I’d have to go to that horrid website again and suffer from the cookie-based after-effects for weeks!!! 🙂
Ah, ha! I see it now, you were trying to trick me!! Marcus!!!!!! Hope you are keeping warm up there, sans snuggly.
…Dang, foiled again !!! LOL
or Huggies (Attends/Depends for the senior crowd) so it won’t matter when he wets himself either
Janice Moore,
More like I realize that Greenland is too large to fit into the booth housing a 6th grade science fair experiment, and as such, doesn’t lend itself to methodically twiddling one input variable at a time so as to empirically determine what happens at the end of a series of such experiments.
Newton used models constrained by observation when he developed his laws of motion and universal gravitation for crying out loud. So did Einstein when he demonstrated that Newtonian physics breaks down at the microscopic level and/or at velocities which are a substantial fraction of the speed of light. Yet we still use Newton’s shoddy models every day in the low-velocity macroscopic world we most frequently experience because the math is easier and theoretical error is so small.
The main problem with climate modelling is that the scale and complexity of the physical system places limits on our ability to observe critical processes at very fine spatial and temporal resolution, and certainly limits our computational ability to emulate them with similarly high fidelity. And now I repeat; the authors of both these studies recognize that problem, and explicitly mention that a main goal of their efforts was to increase observational understanding of the system so as to be able to improve modelling efforts.
Why?
Because making a scientific prediction — a key reason we do science in the first place — about some future state of a physical system always requires a model. No exceptions.
If you don’t think such a method constitutes “bona fide” scientific practice, I offer that you simply don’t have the first clue what it is you’re prattling on about when you mindlessly regurgitate the “observations = good, models = bad” horsecrap popularized by a late, very popular and intelligent science fiction writer who really should have known better.
Great logic, Brandon – we have tested Netwon’s and Einsteins theories many times for many years so so van Tricht must be correct.
“Under particular temperature conditions, however, clouds can be both thin enough to allow solar energy to pass through to the surface and thick enough to “trap” some of that heat even if it is turned back by snow and ice on the ground.” Care to put a number to how often that happens?
Robert B,
Nope, our Pavolvian response to the word “model” is so great that we forgot that modelling is a fundamental principle of science … if indeed we actually realized it to begin with.
No, because “how often” wouldn’t really tell you anything at all about the radiative effect, which is exactly what the authors report in the abstract:
http://www.nature.com/ncomms/2016/160112/ncomms10266/abs/ncomms10266.html
This impact results from a cloud radiative effect of 29.5 (±5.2) W m−2
In response to Brandon at January 12, 2016 at 4:46 pm, it’s not a “Pavlovian response” to “models” that bothers me – I’ve used well-verified mathematical models throughout my schooling and career. I am appalled, however, by some of what passes for models in many areas of so-called science these days, especially as they are often unverified, based on corrupted data, or, worse, based on limited to no data. What does cause a “Pavlovian response” in me is the unverified, unvalidated simulations upon which major international policies are being based.
I have built simulations in my career, and I have used simulations. They are what Pielke (Senior) refers to as steel and concrete (IIRC) simulations, in that they are based on sound physics of mechanical things (in my case, flight vehicles). I know just how hard it is to build a decent simulation when the physics is well defined and there is a vast amount of reputable data against which to verify the model and then the simulation. I also know to trust but verify every single simulation run. No luxury of looking at something like CMIP5 results and saying we’ve done it right.
Climate models, and climate simulations, are world’s more complex than anything I built or used, and I see no evidence of any standard of care being exercised in their construction or the interpretation of their results. Limited to no discussion or documentation of the assumptions. Verification, if done at all, against questionable and limited data.
So, Brandon, you’ve made your point – models are, of course, a part of science and engineering. So are simulations. But I’ve seen how it is done right, and I’ve done it right. I also can see the BS when it is so obvious.
Brandon Gates January 12, 2016 at 4:46 pm
Brandon thank you for the paper.
But also do be careful with those Pavlovian responses,
Robert B January 12, 2016 at 4:17 pm
He said nothing about Models.
We all sometimes have knee jerk reactions,
By the way the Author appears to be a PHD student, Is this part of his dissertation I wonder.
Seems he has done a lot of work with Satellites.
Some observations some assumptions, But how much of it is his own field work?
michael
Retried Engineer Jim,
Everyone is different of course. I think I’m on the mark with Janice:
Or did you overlook Tricky’s shoddy methods?
researchers combined these observations with snow model simulations and climate model data to map the net effect of clouds.
I find it difficult to read that any other way than: using models is a shoddy method. Perhaps she will clarify her meaning if I have taken it incorrectly.
This is the point of the conversation at which it might be a good idea to specify a particular model, and demonstrate that it is unverified.
Then I would think you’d be the world’s biggest advocate for NOT making changes to the system those models represent until you are satisfied by their reliability.
http://www.cesm.ucar.edu/models/atm-cam/docs/description/description.pdf
226 pages. Knock yourself out.
Ok, again, I’d think a retired engineer faced with a dearth of reliable data would be at the head of the line of people saying that changing the radiative properties of the atmosphere is not the brightest idea we’ve had since we allegedly developed the ability to reason.
Which specific BS would that be?
Mike the Morlock,
No, but Janice did, Bob was responding to my response to her, and did so by creatively misinterpreting what I wrote to her.
Dunno, and I’m not seeing the relevance to my main argument here, which is: where’s the glaring discrepancy between the findings of this paper and the other one from 2013?
Brandon,
I have done some modelling in a previous life. I have done one more experiment to confirm my model only to debunk it. I have noticed a small anomaly in my data that when I investigated further showed that my experimental results were only consistent with my modelling because of impurities. And I have gone Eureka only to check though my work and find that the model only fitted the data perfectly because I forgot a pair of brackets.
The work that you cite concedes in the abstract that it is based on modelling and gives a result contrary to conventional wisdom and without actually experimental results to back it up. That gets me drooling, especially when it talks about refreezing at night so not exactly backing up what you claimed.
Robert B,
Allow me to return a favor: Great logic, Robert B, you mucked up a model once upon a time, so Van Tricht et al. must’ve mucked up this one.
Greenland is too big to fit on anyone’s lab bench. How in the hell is anyone going to run experiments on it?
Which claim? May I again remind all and sundry here that the main point of my initial post on this thread was to ask Anthony where the discrepancy is between this study and the one from 2013? Perhaps when y’all are done chasing squirrels around, someone can actually address that?
No, Brandon, a good scientist doesn’t tell people what will happen until they check their modelling thoroughly. Its too easy to make a mistake. “Greenland is too big to check” is not an excuse.
I have just read the abstract but isn’t it talking about sunlight coming through during the day and cloud cover keeping the night time temperatures warm enough to stop the melt water refreezing rather than what you described? Considering how short nights are when day time temperatures are above zero, I wouldn’t have expected much more than the surface to freeze anyway.
Looks like you’re trying to con the gullible who might stray on the site rather than put forward a convincing argument.
*going around in circles?
Me thinks that Brandon Gates’s educational expertise in/of science in general and climate science in particular is akin to that of an Editorial Page Editor of a newspaper or Syndicated Columnist whose verbiage is based solely on selective mimicry, paraphrasing, journalistic plagiarism, quote mining, etc., to please and appease the political beliefs of those who are avid fans of said published media,
Robert B,
I agree with that.
I didn’t write the words enquoted above, though, did I. What I actually wrote was … Greenland is too big to fit on anyone’s lab bench. How in the hell is anyone going to run experiments on it?
… in response to your statement: The work that you cite concedes in the abstract that it is based on modelling and gives a result contrary to conventional wisdom and without actually experimental results to back it up.
“Experimental” is the word I am objecting to here.
The text you quoted beginning with “Under particular temperature conditions” is from the press release for the Bennartz et al. (2013) study Anthony linked to in his OP, not Van Tricht et al. (2015). What they say in the abstract is: Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff.
So, yes, I think your interpretation of the 2015 paper is consistent with what the authors say about their conclusions. The 2013 paper IS talking about a different mechanism for a specific type of cloud which was anomalously present during summer of 2012 over Greenland, and which they believe caused an anomalously large melt season.
I don’t see an inherent contradiction here, do you? If so, why?
“Much” is an imprecise term, but it does imply that you are talking in absolute quantities whereas Van Tricht et al. (2015) are talking about relative quantities. We might not intuitively expect 33% more ice melt under cloudy skies in Greenland than clear sunny skies, but that’s what they believe to be occurring.
I have a different opinion, and that is that you might not actually understand my argument, which from my very first post has been in the form of this question: how does Van Tricht et al. (2015) “fly in the face” of Bennartz et al. (2013)?
I also think you’re not terribly interested in understanding my actual argument, preferring to make up your own on my behalf …
Great logic, Brandon – we have tested Netwon’s and Einsteins theories many times for many years so so van Tricht must be correct.
“Greenland is too big to check”
Brandon, mate, you can not use a few coastal towns to debunk that most of the ice surface is -17°C. You can’t use a picture of a river on ice to prove that AGW is real.
… etc., then attacking your made-up versions for being ridiculous (which they are). And now finally you impute motive: Looks like you’re trying to con the gullible …
What’s the con, Robert B? Does it pay me well do you think? You’re big on evidence when it comes to claims made in peer-reviewed journals about global warming, are you equally big on evidence when it comes to supporting your insinuation of my alleged malfeasance?
“Greenland is too big to fit on anyone’s lab bench. How in the hell is anyone going to run experiments on it?” is significantly different to “Greenland is too big to check”? Are you really complaining that I didn’t scroll up to quote you exactly? Don’t put forward a postulate and call it science if it can’t be tested.
And what do you mean by iterative science?
You did not have an argument by referring to “modelling” of Newton and Einstein. The vast majority of readers know about modelling much better than someone like yourself and know the difference between correct use and its use in climate propaganda.
I can’t be bothered scrolling down to see what other rubbish you wrote. If some kid is still going to get conned, then so be it.
Gates – which triggers additional meltwater runoff: 56 billion tons per year
ristvan – the net loss was essentially zero in 2014, and will in all likelihood have gained about 200GT in 2015
So quibbling about 56 versus 200 versus 2,343,728 cubic kilometers (= GT) total. volume. Let us know when you can actually calculate the rounding error.
+1
DD,
Why is it you are not asking ristvan the same question, as you are relying on his claims (uncited, no less) of net loss in 2014 and probability of a gain in 2015?
Further, why don’t you address the central point of my reply to Anthony, which is, “I’m not seeing the glaring contradiction.”?
I mean, aren’t those questions — oh I don’t know — the kinds of things skeptics are also supposed to ask? Hmmmm?
To actually answer your question, if you really want to reduce the (variously) estimated ice mass gain/(loss) from Greenland to ridiculously tiny percentages, divide whatever rate figures you trust (for whatever reason you apparently trust them) by 5.972 × 10^24 kg … which is also an estimate, but the answer will be well within “rounding error” of zero so as to not make much difference.
You are being disingenuous. The models are pure, unadulterated crap. Trying to “improve” them by putting lipstick on them doesn’t change the fact that they are crap. What they are doing isn’t science at all. The agenda is simply keeping the CAGW gravy train rolling along for at least a bit longer.
Heh. Way-to-go, Bruce Cobb! 🙂
Add marshmallow creme, ketchup, Tabasco sauce, or…… TONS OF GRAVY (man alive! they must have swilled an ocean-full by now, lol)… climate models are JUNK!
A video metaphor – ya know, watching all those pitifully apt analogies in that little video clip, you kind of start to feel sorry for those poor AGW duffers (bullied by their leadership, etc…) …. then you remember …. and – NOT!
“How to Eat Fried Worms” (youtube)
Bruce Cobb,
Yeah, those high-falutin libruhl warmunists must be pretty stoopid to have not been able to have come up with a better scam. I mean, 1988 was how long ago and there’s still no worldwide carbon tax? Dang man, they’re fat rolling in your money. And they must be egregiously incompetent to have not thought about tweaking the already falsified surface temperature records so as to better match the output of the imaginary “physics” coded into those models, eh?
Brandon Gates January 12, 2016 at 5:02 pm
Brandon, we can go round and round, types of clouds, Models, number of surface measurement stations. But at the end of the there is only one metric for determining whether or not not the Greenland ice sheet is melting away. Realtor signs. No don’t throw you hands up and toss it off as nonsense. Think, if there were truly the slightest possibility that it was really happening don’t you think every scam artist ever born in the real-estate business wouldn’t be running ads for “pristine estates” not seen since days of the cavemen. Think about the allure, vast tracks of all yours (once the last of the ice melts) Devil take it man, scam artists are selling development “lots” on Mars predicting colonization. AGW is so over the top real estate sharks won’t ever touch it.
So when the “For sale signs” go up then it time be worry.
michael
@ Mike D. (not a) — +1!
(Re: 5:48pm)
Follow – – -> the – – -> money.
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
Hope you got to take that youngest boy out to see the Massachusetts historical sites you were hoping to.
Here’s to a fine commenter and a great 2016 for you and your family!
Mike the Morlock,
I wouldn’t think of it.
I know a number of real estate sharks, and what they really like are developed properties in places where a bunch of people already are and even more want to be … like sandy beachfront properties in warm climates, not desolate cold places with rocky beaches, crappy soil, little established public infrastructure, and essentially zero net migration rates. If SLR starts putting a more noticeable bite into patches of dirt covered by 100 year leases and planted with hi-rise commercial structures, the for sale signs you’re looking for will be in places like Miami, not Nuuk.
Earlier Brandon gave an exact back radiation mumber, but at the same time said how often this occurs is irrelevant?
We would also need to know exactly what percentage of the night time Ts were above freezing anyway. Indeed, we would have to know not only how many nights were below 32F, but for how long and what geographical area.
David A,
No, the authors gave a bounded estimate of the mean:
http://www.nature.com/ncomms/2016/160112/ncomms10266/abs/ncomms10266.html
This impact results from a cloud radiative effect of 29.5 (±5.2) W m−2
By definition, the mean does not have a frequency of occurrence, so yeah, how often the mean occurs is completely irrelevant.
Greenland is freaking huge and sparsely populated with ground-based instrumentation, so you’re not going to get “exact” calculations of anything. Further, percentage of time above/below freezing tells you diddly squat because, among other things, ice melts faster the further ambient temperatures get from its melting point. So a frequency distribution of temps is the better place to start for back of napkin calculations.
Careful now, however; use too many napkins and pretty soon you’ll have yourself a full blown model, which is apparently a no-no for some folk in these parts.
Poor, delusional Brandon, heroically defending his “models”, not realizing that they aren’t reality- based, but rather that a large component of the climate “forcing”, via man’s CO2 is simply assumed. These sorts of “studies” are merely make-work for those in the Climatist industry, and to keep the Warmist narrative alive. Further “studies” will no doubt attempt to show that clouds in the Arctic have increased due to warming, thus providing another, mythical positive feedback for them.
Sounds like we lack the information to build an accurate model of this and, as observations of failed IPCC models demonstrate, our understanding of clouds is poor.
The mean backradiation is certainly “diddlysquat” more so then knowing how much time is spent on which side of the phase transition of water from liquid to solid. If night time T is consistently below that line, back radiation mean is of no major consequence as the ice did not melt mean during said mean back radiation.
Knowing the back radiation without an accurate corresponding sliding chart on the day time S/W reduction, Will further increase the error margins of any modeled estimate.
Bruce Cobb,
I’m not sure which assumption you believe to be invalid:
1) That the observed increase in atmospheric CO2 is mostly due to human activity
2) That the increase in CO2 retards radiative heat loss from the planet, thus resulting in a greater portion of absorbed solar radiation being retained, ultimately resulting in warming of the oceans, surface, and troposphere.
Perhaps both? But yes, those are the operative assumptions, and I assume them to be true in the same way that I assume the sun will set over my western horizon later today and rise tomorrow over the eastern one, or that the tide tables I keep handy are useful for checking whether a particular date and time is a good one for taking the boat out for a spin, or that a 24 hour weather forecast is a good thing to check in addition to looking at what tides are expected to do.
It’s been my personal experience that known physical mechanisms are good for making useful predictions.
I don’t think you’re wrong about that, and I’d actually be surprised if it hasn’t already been investigated. I can think of one plausible physical mechanism: oceans at lower latitudes warm, increasing vapor pressure at the surface. The warmer atmosphere is better able to hold additional moisture, the net result is increased evaporation, but not necessarily increased cloud formation. [1] As higher latitudes are already known to exhibit amplified trends relative to lower latitudes, moisture which would have otherwise precipitated out at higher latitudes remain in the form of clouds.
We can already check this hypothesis against observation, albeit somewhat crudely:
CRU TS3.23 annual mean cloud fraction 0-360E 90-65N (source: KNMI Climate Explorer)
http://4.bp.blogspot.com/–unLDrlv_bY/Vpap8sUQMcI/AAAAAAAAAig/V1IE5MrVm60/s1600/icru_cld_0-360E_90-65N_n_mean1_anom_30.png
No immediately apparent trend over the entire interval, but a lot of (pseudo)periodic variability which is almost certainly due to things like AMO and PDO for the longer cycles and ENSO and others for the shorter inter-annual cycles.
—————
[1] Up to here is already on the books as part of the explanation for positive water vapor radiative feedback.
David A,
All models are always wrong. It’s their defining characteristic that they are simplifications of much more complicated processes. Deciding whether a given model is useful is a subjective proposition, and is highly dependent on what one personally considers “accurate” enough for the model’s intended purpose.
The IPCC does not consider the CMIP5 ensemble a failure, you however do. From that I consider it likely that you think those models should be doing something they are demonstrably not able to achieve.
As typical in this forum, that purpose is not stated, nor is what you consider “accurate” enough to suit that purpose.
Clearly, the authors of this paper believe that our understanding of cloud processes in Greenland needs to be better, hence a main purpose for them doing this study. As is also typical in this forum, you don’t give them any credit for attempting to do what you are implicitly asking: achieving better understanding of clouds.
Your conclusions don’t follow from premises. It’s not time above or below a certain fixed threshold, but the frequency distribution of all experienced temperatures. By way of illustration: all else being equal, a liter of liquid water will freeze solid faster when ambient temperature is -40 C than it would in -5 C ambient temperature. The converse is true for the melting process, higher ambient temps will melt the same block of ice faster than temps only slightly above freezing.
IF we had observational data at very high temporal and spatial resolution, we could build a reasonable statistical model of ALL the relevant factors (temperature, cloudiness, humidity, pressure, solar and thermal radiative flux, latent and sensible heat flux, horizontal and vertical fluid velocities, etc.) and attempt to draw conclusions on a purely empirical basis.
Apparently the authors of this study believe that we don’t have enough adequate observational evidence for Greenland, so they built a model constrained by and combined with the observations we do have to estimate the relative frequencies of what they think are the relevant parameters. The way I read it, one estimate based on output from that model is: This impact results from a cloud radiative effect of 29.5 (±5.2) W m−2
I don’t take that to mean that they plugged in the mean 29.5 W m−2 as a model parameter and from that computed an estimated difference in melt rate, I take it as an estimated value based on results of their model runs. The big hint there is the (±5.2) W m−2 error estimate provided with the mean forcing.
Again you are treating “accuracy” as something which is an either/or property. It’s not; accuracy is a quantified property. That said, yes, it follows that less accurate observational data inherently increases the error bounds of any estimates or calculations derived from those data.
I’m pretty sure these authors know this — I myself learned it in high school and this paper is published by Nature, which is a prestigious for-profit journal whose business model depends on not letting truly obvious crap get by their peer reviewers on a regular basis.
Brandonberg, your walls are crumbling when you talk about the sun rising and the sun setting.
Why is that? Have those rocket boys at NASA been fooling us on heliocentrism all this time or something?
Robert B,
Yes. It’s not an isolated incident either. Again, here are two other previous examples of you inventing arguments for me out of nearly whole cloth:
Great logic, Brandon – we have tested Netwon’s and Einsteins theories many times for many years so so van Tricht must be correct.
Brandon, mate, you can not use a few coastal towns to debunk that most of the ice surface is -17°C. You can’t use a picture of a river on ice to prove that AGW is real.
You are aware of the concept of strawman fallacy, yes? I consider it dishonest and annoying.
Here we go again: where did I ever say that the models used in this paper could NOT be tested?
Seriously? Form a hypothesis, test it. If the testing reveals other phenomena not explicitly considered in the original hypothesis, extend the original hypothesis to form a new one and test that with additional observation. Lather, rinse, repeat.
Why not? What’s your definition of “model”?
An aside: Newton to Einstein is kind of a text book example of iterative science at work.
Ok, please explain to me how you know how much the “vast majority of readers” know about modelling, and how it is you know exactly how much I know about it?
Or just review your prior statement: Don’t put forward a postulate and call it science if it can’t be tested.
It looks to me like you can’t be bothered to address my actual arguments, and much prefer to make up your own … all the more easy to demolish it.
Says the guy who refuses to properly recognize my actual arguments even after he’s been challenged on it. Man you’ve got some sack on you, doncha.
“Greenland is too big to fit on anyone’s lab bench. How in the hell is anyone going to run experiments on it?” was paraphrased as “Greenland is too big to check”? Is that inventing an argument?
You brought up Newton and Einstein when someone pointed out that the researchers above didn’t come to a conclusion from observation but modelling that was unverified by experiment (because it doesn’t fit on a lab bench. Happy now?).
Iterative science? If you are wrong, try again.There is no set definition as to what “try again” is. Just something different. Iterative is actually repeating a process as in calculations used to find solutions to equations.
Its like having to listen to an academic being described as doing evidence-based research.
-” What’s your definition of “model”?”
Newton’s laws and Einsteins theories were found to be true descriptions of what the physical world does. There is no reasoning behind Newton’s Laws.They were proposed from observation and not reasoning from prior knowledge. There is reasoning in theories such as “What if the speed of light was a constant?”
Look up Einstein’s cosmological model that was derived from his theories and other limited knowledge of the universe, which was wrong.
Says the guy who has pointed out how superficial and stupid your actual arguments regardless of how you try to dress them up afterwards?
Robert B,
Not really because you are still mashing my words together wrongly and making me say things I did not intend to, nor would not. Let me attempt to end your obviously continued confusion.
Experiment in this context to me means setting up some physical apparatus and methodically changing one input parameter at a time to see how it affects one or several output parameters. We can’t validate a numerical model of Greenland against an experimental physical model of Greenland because the latter is too massive to fit on our lab bench so that we may twiddle dials and see what comes out the other end of the black box.
We CAN validate a numerical model of Greelnand against observational data. And we should. For whatever reason, you apparently think these authors did not, and somehow think I am defending them for not doing so. You could not be more wrong about the latter.
I’ve got no problem with that definition either, with the one caveat that we are always going to be wrong. So I see one aspect of the scientific method as the process of (hopefully) becoming incrementally less wrong.
Tut. More like the best known explanations for observed phenomena to date. Gravity still cannot be explained by the Standard Model, so there is yet still work to do.
What the … ?
Sure, and there’s reasoning behind, “What happens when a photon is absorbed by a gas molecule in the atmosphere, and quantum mechanics does not allow us to predict in advance which direction it might be re-emitted as a response?”
Been there, done that. My actual favorite Einstein quote along those lines is, “God does not play dice with the universe.” Assuming for sake of argument that his worldview was correct, it literally would have been impossible to change his mind.
As I’ve mentioned before, you first need to understand my actual argument, which you have no hope of doing so long as you continue to ignore what I actually write and then proceed to make it up for me. I can start over if you’d like: everything Newton and Einstein formalized as a law of nature is a model according to my defintion of that word. It doesn’t matter to me whether it came from extending prior knowledge and predicting phenomena in advance (Einstein) or empirically from observation (Newton).
Generally speaking, climate models are both. And like both Netwon’s and Einstein’s models, they’re all wrong, by definition.
Pure BS. You did the standard reference to Newton and Einstein when someone pointed out that only in the modelling did they observe what they claim. Here is a reference to a definition of a Scientific Law.
http://chemistry.about.com/od/chemistry101/a/lawtheory.htm
From purely empirical observations he proposed a law without understanding gravity.
Here is how you used the adjective “iterative”
I’ll let readers judge if you really understand half the stuff that you write.
That referred to quantum mechanics and not relativity. “Been there, done that” Pigs arse.
I’m going to stop. the threads too long and life’s too short.
When will someone tell KU Leuven and the rest of the CAGW nob, that model simulations do no count as “evidence.”
…They have models that PROVE that models are indeed evidence..but you can’t look at them because you might make fun of them !!!
“With climate change at the back of our minds, and the disastrous consequences of a global sea level rise, we need to understand these processes to make more reliable projections for the future. Clouds are more important for that purpose than we used to think.”
Seems rather “unsettling” to me.
Until computers become several orders of magnitude faster/bigger there will no modeling of clouds. Good luck with the conjecture.
Dang -left out ‘be’
The balancing effect depends up on the type of clouds [thickness, ariel spread]. This is a weather condition. It may not be the same all the time. In this, several general circulation factors [formation or non-formation of circumpolar vortex] play an important role along with oscillation system. Because of such wide ranging variations play important role on ice melt, the seasonal march of the ice melt in different years move up and down over the average. 1912 has come down and now it has moved up — there might have been lower than 2012 in the past. The winter high changes very little and the maximum variarion is in summer low.
Dr. S. Jeevananda Reddy
I think this the lead author, not sure what to make of him.
Still trying to find the “paper”
https://www.linkedin.com/in/kristof-van-tricht-84a76232
michael
These cloud blankets that we often read of are fascinating.
It’s easy to observe that a blanket on a bed does not keep the bed warm, but when I get into the bed it does keep me warm. I have concluded that there is something about me that is crucial to the whole blanket/bed/warm scenario.
If the blanket analogy in snow-covered Greenland is apt, I am forced to wonder; if clouds keep Greenland warm, what makes Greenland warm in the first place? Where did that warmth come from, that is trapped by the cloud blanket?
And, where did the cloud come from, that trapped the warmth that Greenland enjoys? Is it possible that, as the cloud mysteriously piled up over Greenland, warmth also snuck in surreptitiously?
Certainly, on planet Average, the sun warms the surface and the surface warms the sky, but that clearly isn’t the case at the top of the globe, where, for several months, no sun is doing any warming, and yet… some warmth is there. The same is true here, on Vancouver Island, where we don’t see the sun for days at a time but the diurnal temperature variation is not even a handful of degrees.
Do we have, like, an electric blanket?
mebbe,
I think it’s an apt analogy. In general at the surface, the tropics are net energy gainers and higher latitudes are net energy losers. The differences are made up by heat movement from equator to each pole; the primary transfer mechanism is the oceans and to a lesser extent the atmosphere.
Brandon,
Your generalisation is not disputed but it’s not very informative. When you speak of a cloudy day, as opposed to a clear day, the movement of air and heat on any given occasion is essential to any consideration of who is doing what to whom.
It is seldom the case, here, that the cloud that is shading me from the sun comprises water that evaporated more or less where I’m standing; it came from many miles away, over the Pacific. The energy contained in that air mass, and that which is released as droplets condense above me, is more relevant to the temperature of the air I’m breathing than the sun that I haven’t seen for a week. For two days, we have been receiving warmish, moist air from over towards Hawaii. It has been raining onto frozen ground and the ice is slowly diminishing. Of the meagre warmth we have, what is derived from sunshine on the top of our clouds is only significant when contrasted with the putative back-radiation that originates in the ice under our feet.
There’s a lot more heat capacity in a cloud full of moisture than in a clear sky and that heat isn’t locally produced.
mebbe,
Yes of course. I see it as somewhat academic that determining what goes on in a complex system requires accounting for as many factors as possible.
Thus far, I’m not seeing how that is inconsistent with my generalized statement of heat transfers across great distances from the equator to poles mostly by way of the oceans and somewhat by way of the atmosphere.
Now I’m not following. It’s late for me though, perhaps it will make more sense when I read it again tomorrow.
I agree with that, but have no idea how that rebuts anything I’ve written, or indeed how it contradicts the findings of this study that everyone here seems to think I’m attempting to defend. I mean, their conclusions sound plausible to me (and not actually against “conventional wisdom” as they write in the abstract), but the paper is paywalled and I’ve not been able to glean much from reading the abstract and looking at the figures.
I can say that in their figures they distinguish between clouds composed mostly of ice vs. ones composed mainly of liquid water because of their differing optical properties, but I’d also reckon they’re aware of the need to account for phase changes in their energy budget. (As a rule, I assume that professional scientists who have gotten published in Nature haven’t overlooked such basic physics … but that’s just me I suppose.) As well, it seems to me that it’s going to snow more often in Greenland than it rains as compared to where you live in lower latitudes, so snow falling on already frozen water isn’t going to involve the kind of latent heat transfer that rain falling on ice would.
In sum, I really don’t know where you’re going with this line of questioning. But again, I’m up past my bedtime and perhaps it will click into place for me tomorrow.
mebbe January 12, 2016 at 8:52 pm
Brandon,
Your generalisation is not disputed but it’s not very informative.
Despite turning in a passable performance in this thread, I think Mr Gates has gone off the rails here. First of all, my recollection is that atmospheric transport of energy is actually much larger than the oceans. This was pointed out to me by Nick Stokes. Sorry, can’t remember the paper(s) but I do recall that Trenberth was co-author ons or more of them. It sticks out in my mind because I had always assumed otherwise.
But the large flaw in the response to mebbe is that while it is true that tropics are net absorbers of energy and higher latitudes are net losers, these things have nothing to do with answering mebbe’s question. Mebbe’s question is more easily answered in a cold winter evening with no a whisper of wind or ocean transport to be had.
As mebbe points out, he is the heat engine that warms up the bed. Greenland has no heat engine, it is bone cold, so how can it radiate sufficient heat for a cloud blanket to keep it warm? The answer is that temperature is relative. If we consider the problem from the perspective of degrees Kelvin, suddenly the surface of earth is +273 (rather than 0 C)which is hot as blazes compared to absolute zero. If there were no atmosphere, the surface would be exposed to the temperature of out space, about 3 degrees. The more things there are (like clouds) in between the surface and space, the more the effect works on the exact same principals as the blanket on your bed. Now if YOU were standing on the ice sheet, you’d be damn cold because the ice would be sucking the energy out of you and the immediate air mass. You’d both be hotter than the ice. However, without the clouds, you’d be even colder. Way colder.
davidmhoffer,
I believe the paper you are speaking of is Trenberth and Stepaniak (2004): http://onlinelibrary.wiley.com/doi/10.1256/qj.04.83/pdf
Figure 6 on page 12 of the document does indeed show that the atmosphere is the primary poleward energy transport mechanism. I apologize for not checking my own assumptions and, more to the point, for not making it explicitly clear that I was assuming. I thank you for the correction because I do not like believing wrong things or conveying wrong information.
I largely agree with the remainder of your post, especially the point that temperature is relative. However, I don’t think it answers mebbe’s question any better than my original answer, the question being, “where does the energy come from?”.
Yes, that simplification works well to illustrate the “blanket” effect the atmosphere has for energy already present at the surface. Doesn’t answer how the energy got there to begin with. Remember, the premise of this paper is that Greenland is, on average, warmer when it is cloudy than under clear skies, implying that direct insolation did not make Greenland warmer during the time interval studied. Obviously, the ultimate energy input was insolation; however, if the conclusions of this paper are true, that solar energy MUST have been absorbed somewhere else and moved to Greenland by some other means. [1]
mebbe apparently wants further details on that process, and apparently questions the radiative insulating mechanism of clouds. Which is great … I think those are excellent and entirely appropriate questions to be asking. Unfortunately, they are difficult for me to answer beyond the admittedly simplistic (and in at least one case, flat-out wrong) fashion I have already done.
—————
[1] Only if I understand the conclusions of this paper properly, and I may not. The 2013 study pointed to a particular type of low thin cloud which allowed some sunlight through, but effectively absorbed outbound LW and re-radiated some of that back to the surface, effectively resulting in a very anomalous warming episode. So, this is one mechanism to keep in mind; however, my reading thus far is that this is not the net effect of clouds observed/modelled over the period of the present study.
Brandon,
I’m not contradicting your vague generalisations and I’m not disagreeing with the little that I’ve seen of the paper.
Perhaps, I was prolix but my point is that clouds don’t just keep Greenland warm, they are the source of the warmth. When it’s been -40 for a week and it becomes cloudy, it invariably gets warmer than -40, not because the cloud trapped the -40 heat, but because the incoming, moist, rising air brought a lot of heat with it.
This is not to dispute that interposing a layer between two other layers will delay equilibration of their thermal states.
mebbe,
Ok, that was my impression. Twice now on this thread I must admit to wrong assumptions, with apologies.
I did understand that was what you were driving at, but I was too fuzzy last night to articulate it. That still reads to me as contradicting this study, but as the paper is paywalled I haven’t been able to dig into its guts.
I buy that, and it certainly is consistent with poleward energy transport by way of advective atmospheric processes.
Thanks for making that clear. So basically I understand your argument to be that you think the warming observed in Greenland when it is cloudy is due more to atmospheric advection which just happen to be associated with clouds rather than cloud formation over the surface “trapping” heat that had already gotten there by some other means.
You could be right; however, I maintain that it is at odds with the conclusions of this study. Which is fine by me. I cannot confidently defend the authors’ conclusions against some other plausible hypothesis as yours, and it’s not my intention to do so. You do raise interesting points and questions, for which I thank you; I am enjoying this discussion.
davidmhoffer:
“Greenland has no heat engine, it is bone cold, so how can it radiate sufficient heat for a cloud blanket to keep it warm? The answer is that temperature is relative. If we consider the problem from the perspective of degrees Kelvin, suddenly the surface of earth is +273 (rather than 0 C)which is hot as blazes compared to absolute zero. If there were no atmosphere, the surface would be exposed to the temperature of out space, about 3 degrees. The more things there are (like clouds) in between the surface and space, the more the effect works on the exact same principals as the blanket on your bed. Now if YOU were standing on the ice sheet, you’d be damn cold because the ice would be sucking the energy out of you and the immediate air mass. You’d both be hotter than the ice. However, without the clouds, you’d be even colder. Way colder.”
It’s not a question of because Greenland is cold it therefore can’t radiate enough heat for cloud to warm it.
All things radiate when at a temperature above 0K.
Therefore the surface of Greenland radiates (at whatever temperature it is currently at).
That radiation consists of LWIR that WV, and particularly ice crystal absorbs and re-radiates very well.
There is therefore SOME IR back-radiated to the (snow/ice) surface of Greenland.
Thin high cloud causes surface temperatures to arrest their fall-away once radiation conditions (clear skies/dry troposphere and calm winds) are interrupted by invading Ci/AC cloud – it would also happen in windy conditions but the wind (turbulent mixing) would hide it.
It’s just a meteorological fact.
I have seen this on multiple occasions as a meteorologist on duty. The more extreme the surface temp (as in very low) the greater is the arresting effect of the fall-away as the high cloud invades.
Back-radiated IR from cloud at a temperature of (say) -30C from cloud 5 miles aloft DOES do this even in temperate zones (England in my case).
It was an every-day reality to me in Arctic air-mass winter-time forecasting.
Basically we have a mirror-like effect from a snow surface to Ci/AC cloud. Emission from ice crystal>absorption by ice crystal (cloud )> re-emission > repeat. When both absorber/emitter are at similar temperatures the effect is greatest.
It is part of what is meant by “Polar amplification”
“Now if YOU were standing on the ice sheet, you’d be damn cold because the ice would be sucking the energy out of you and the immediate air mass. You’d both be hotter than the ice. However, without the clouds, you’d be even colder. Way colder.”
EXACTLY – you got it!
Brandon says;
“Remember, the premise of this paper is that Greenland is, on average, warmer when it is cloudy than under clear skies, implying that direct insolation did not make Greenland warmer during the time interval studied.”
Indeed.
Over a snow/ice surface (which ~99% of Greenland is 99% of the year) – then insolation is largely reflected back to space …. under clear skies. Now put cloud there and the above eureka statement applies (“way colder”).
Even in England at a Lat of 53N (where I live) daytime temps will only rise for a short period in full sun over a fresh deep snow cover around the middle of the day in deep winter – at all other times of the day (in good radiation conditions) the temp will either hover or continue to fall-away. In other words solar absorbed only briefly exceeds solar radiated to space by the snow cover..
Cloud in polar regions, by definition, implies advection of an air-mass from warmer southern parts – it has moisture which condenses as it cools moving north (in general terms). That is where the vast majority of “warmth” comes from in Greenland.
Left to it’s own devices a Polar climate would condense-out all moisture as ice onto the ground in winter and sublimation/evap in summer is limited compared with an open ocean – one reason why melting sea-ice is increasing sensible and LH transport into the polar trop (esp in the KARA sea area).
Mebbe:
“When it’s been -40 for a week and it becomes cloudy, it invariably gets warmer than -40, not because the cloud trapped the -40 heat, but because the incoming, moist, rising air brought a lot of heat with it.
This is not to dispute that interposing a layer between two other layers will delay equilibration of their thermal states.”
YES – that is advection or transport of heat as I state above. The two effects are not mutually exclusive however, and on the slow advance of Ci cloud ahead of a warm front the radiative effect will take place most noticeably first before the warm air arrives PLUS there are innumerable occasions when patchy Ci/Ac cloud overlies the surface cold air and the warm air-mass goes over the top and is delayed or never arrives at the surface.
Brandon,
I share the sentiment. Props to you for your good-natured perseverance here in hostile territory.
mebbe,
I appreciate that. I fear however that some cracks are appearing wrt some of the more ludicrous comments by others on this thread. [sigh]
We lose ice when it is cloudy, we lose ice when it is sunny. Greenland has been in crisis for thousands of years.
“On the one hand, [clouds] help add mass to the ice sheet when it snows. On the other, they have an indirect effect on the ice sheet as well: they have an impact on the temperature…”
So, which effect is greater? On balance, do clouds add more mass to the ice sheet or reduce more mass? I don’t see where this article says one way or the other. If they add as much or more mass than they subtract, what’s the cause for alarm?
I would go back a bit further.
Cloud modelling is lacking at the moment. We need to consider the energy flow from TOA to the surface, via different densities of clouds at different heights at different temperatures and wind speed.
We need to consider energy travelling from the surface upwards to TOA via the same clouds as above.
I see no reason why these paths must be linear or equal.
Uhhh… Here in Northern Ontario, we know that in winter, a clear day is cold and a cloudy day is warm. The cloudy days mean winds are from the south. More melting on a warm day? Whouda thunk it? — John M Reynolds
In layman-ese, isn’t this just the effect of water vapor that is the predominant greenhouse gas?
It’s hardly clear why such an effect should be restricted to Greenland. We would expect similar behavior at any place with deep snow. So has it been studied for the general case? –AGF
Claim: Greenland ice sheet melts more when it’s cloudy
Posted by Anthony Watts
From KU Leuven and the
“department of annoying back-radiation”
____
Yes, Anthony Watts.
1. Claim: Greenland ice sheet
melts more when it’s cloudy
2. from Greenland KU Leuven “department of annoying back-radiation”
____
1st sentence citatiting thesis
2nd sentence presenting antithesis
3rd let them commenters work it out!
_____
high score fore
1st nailing the point
2nd condensing the reproach
3rd let’s learn by challenge.
Thanks – Hans